As the plastic article is increasingly widely applied, a plasticizer product is introduced into many industries of national economy, especially for the application thereof in industries of food, medicine, toys, hygienic products and the like directly related to human health, which brings about higher health and safety requirements to the plasticizer industry. Detoxifying of the plasticizer industry has become a major livelihood issue concerned by the public, and transformation and upgrading of industry from the petrochemical plasticizer to a biological and non-toxic plasticizer have become imperative. In European countries, American, Japan and South Korea and the like, the traditional petrochemical plasticizer has been prohibited in many industries by office order, and instead related green and nontoxic plasticizer species such as citrates, dihydroxy alcohol esters and epoxidized plant oils are used. The European Union provided temporary regulations in 1999 to limit the application of the phthalate plasticizer in children's toys, and after multiple revisions the new European Toy Safety Directive (No. EC765/2008) was officially put into implementation by the European Union in 2011, which expressly stipulated that no petrochemical phthalate plasticizer should be added into toys and other articles for children; the REACH regulations promulgated by the European Union in 2007 explicitly prohibited the application of the phthalate plasticizer in industries closely related to human health; and in early 1990s, the U.S. Environmental Protection Agency (USEPA) had already limited the application of many kinds of phthalate plasticizers in industry fields with high requirements to environment protection and hygiene, such as medical plastic articles, food packages, children's toys and the like; in 2008, President Bush officially signed the CPSIA Act to explicitly limit the application of 6 kinds of phthalate plasticizers in fields of food packages, children's toys, and medicine; and Australia, Japan, South Korea, Argentina and the like have successively promulgated multiple restrictive orders for the application of phthalate plasticizers.
A petrochemical phthalate plasticizer is dominated in the plasticizers produced in China (over 80% market shares). However, the phthalate material is an environmental hormone, which has relatively strong reproductive toxicity and certain carcinogenicity. In China, various health and safety problems have been induced by excessive and improper use of the traditional petrochemical plasticizer. For example, in 2005, the safety problem of fresh-keeping film occurred in Japan induced great attention of Chinese people to safety of plasticizers; in 2008, the European Union promulgated import restriction to toys from China; in 2011, the plasticizer scandal happened in Taiwan; in 2012, the plasticizer crisis of white spirit occurred in China; etc. With ever-increasing pressure of petrochemical resources and improvement of the living standard of people, a variety of problems caused by the plasticizer gain broad attention from people, and related laws and regulations are being perfected day by day; the “Hygienic Standard for Cosmetics” promulgated in 2007 added 3 kinds of phthalate plasticizers into the prohibited group; the Hygienic Standards for Uses of Additives in Food Containers and Packaging Materials promulgated in 2008 limited the application of 7 kinds of phthalate plasticizers; and in 2011, the Ministry of Health in China added phthalate substances into the list of illegal additives in food.
With respect to catalyzing technology, the catalyzing technology of relevant foreign production enterprises still is still highly confidential, while Chinese enterprises still use in production sulfuric acid as the main catalyst, which causes serious pollution and poor product quality, showing a significant disparity from the foreign catalyzing technology. New catalysts such as sulfonic acids, solid superacids, heteropoly acids have been developed in scientific researches, and there are some researches related to enzyme catalyzing technology. These enzymes have overcome the disadvantages of strong corrosivity, many side reactions, unmanageable reaction waste liquids of traditional concentrated sulphuric acids, but there are still disadvantages of high cost, harsh reaction conditions, high power consumption and raw material consumption, complex post-processing, poor product quality and the like in different degrees, which greatly blocks the industrialized application of the catalyst. With respect to engineering technology, Chinese enterprises still mainly use the batch production process, and the relevant enterprises are of small scales, and have unstable production, high power consumption and high discharge, which greatly blocks large-scale industry development and the relevant application of biological plasticizers.
CN1204970C discloses a reaction-controlled phase transfer catalyst used for oxidation and an oxidation process for catalyzing epoxidation of a double bond by using the specifically designed catalyst, wherein the catalysts of said catalyzing system can react in the presence of hydrogen peroxide to obtain an active substance dissolved in the reaction system, thereby catalyzing the epoxidation reaction; however, when the hydrogen peroxide is completely consumed, the catalyst is reverted to the original structure and thus precipitated out, thereby realizing recycling of the catalyst. Currently, said catalyst system has been successfully used in preparation of propylene epoxide and epoxy cyclohexane. However, there are a series of problems of said catalyst system, such as the need of using a large amount of organic solutions, which causes that the successive processing is complex and consumes power. CN102875492 A provides a novel method for preparing an epoxidized fatty acid ester from an unsaturated fatty acid ester. The epoxidized fatty acid ester is generated by epoxidizing the unsaturated fatty acid ester using a metal-substituted polyoxometalate compound as the catalyst and using hydrogen peroxide as the oxygen source in the presence of neither other organic solvents nor organic peroxy acids. However, this method needs to prepare metal-substituted polyoxometalate as the catalyst, and thus is complex in the process. CN102876462 B discloses a method for preparing high-quality epoxidized soybean oil, including mixing an aqueous hydrogen peroxide solution with an aqueous formic acid solution; then adding a catalyst and a stabilizer; pumping soybean oil and the aforementioned mixture into a micro-channel modularization reaction device and maintaining a reaction residence time of 2-12 min; reacting at 65-95° C.; introducing the reaction products into a separator, adding an aqueous NaCO3 solution and standing for layering; removing the lower aqueous solution and water rinsing the upper organic phase; and removing the moisture via rotary evaporation so as to obtain the high-quality epoxidized soybean oil. However, this method needs the addition of a stabilizer and has a high raw material cost; meanwhile, it also needs the addition of sulfuric acid as a catalyst, which results in the occurrence of a ring-opening reaction as a side reaction and the increase of three wastes. CN 102993133 B discloses a method for preparing an epoxidized fatty acid methyl ester with a micro-reactor in one step, wherein the addition of a stabilizer and the addition of sulfuric acid as a catalyst are also involved, and thus it may cause ring opening of an epoxy group, reduction of the epoxy value of the epoxy group, and inevitable increase of the three wastes.
CN104560407 A discloses a novel method for preparing an epoxy plasticizer, including mixing a highly-concentrated hydrogen peroxide and a highly-concentrated formic acid at room temperature to obtain a highly-concentrated peroxyformic acid mixture; then feeding soybean oil into the reaction equipment in one time to start an exothermic self-initiated reaction until the temperature is 60-70° C.; then reacting at a controlled reaction temperature of 70-90° C. for 3-4 hours; performing centrifugal separation to remove the aqueous phase; and dehydrating the crude oil phase, wherein the epoxy value of the resultant epoxidized fatty acid ester may up to over 7.0. This invention avoids the use of sulfuric acid as the catalyst, and thus avoids the large amount of three wastes. However, there are significant potential safety hazards in the early production of the highly-concentrated peroxyformic acid mixture and the safety level of the process flow is low, which easily causes an exploration.